Add cmake_parse_arguments() to `tablegen()` CMake function

[mehdi_amini]

Summary

This support "DEPENDS" and "EXTRA_INCLUDES", allowing in particular
to inject include paths to a tablegen targets without forcing to go
through the global INCLUDE_DIRECTORIES property.

[mehdi_amini]

Fix typo

[stellaraccident]

Thanks!

llvm/cmake/modules/TableGen.cmake

95

Can be for a followup, but I have found this transform to be fragile when empty items are present (the resultant error is quite bad since the "-I" eats the next argument, which then causes it to think the following argument is a source file). It was possible to have this happen before, but now that it is "user serviceable", we should be more defensive.

Can you add (before the TRANSFORM ... PREPEND):

list(REMOTE_ITEM tblgen_includes "")

llvm/cmake/modules/TableGen.cmake

 # LLVM_TARGET_DEFINITIONS must contain the name of the .td file to process,
 # while LLVM_TARGET_DEPENDS may contain additional file dependencies.
 # Extra parameters for `tblgen' may come after `ofn' parameter.
 # Adds the name of the generated file to TABLEGEN_OUTPUT.
 
 function(tablegen project ofn)
+  cmake_parse_arguments(ARG "" "" "DEPENDS;EXTRA_INCLUDES" ${ARGN})
   # Validate calling context.
   if(NOT ${project}_TABLEGEN_EXE)
     message(FATAL_ERROR "${project}_TABLEGEN_EXE not set")
   endif()
 
   # Use depfile instead of globbing arbitrary *.td(s) for Ninja.
   if(CMAKE_GENERATOR MATCHES "Ninja")
     # Make output path relative to build.ninja, assuming located on
function(tablegen project ofn)
   # a tablegen change, as cmake does not propagate file-level dependencies
   # of custom targets. See the following ticket for more information:
   # https://cmake.org/Bug/view.php?id=15858
   # The dependency on both, the target and the file, produces the same
   # dependency twice in the result file when
   # ("${${project}_TABLEGEN_TARGET}" STREQUAL "${${project}_TABLEGEN_EXE}")
   # but lets us having smaller and cleaner code here.
   get_directory_property(tblgen_includes INCLUDE_DIRECTORIES)
+  list(APPEND tblgen_includes ${ARG_EXTRA_INCLUDES})
+  # Filter out empty items before prepending each entry with -I
+  list(REMOVE_ITEM tblgen_includes "")
   list(TRANSFORM tblgen_includes PREPEND -I)
 
   set(tablegen_exe ${${project}_TABLEGEN_EXE})
   set(tablegen_depends ${${project}_TABLEGEN_TARGET} ${tablegen_exe})
 
   add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${ofn}
-    COMMAND ${tablegen_exe} ${ARGN} -I ${CMAKE_CURRENT_SOURCE_DIR}
+    COMMAND ${tablegen_exe} ${ARG_UNPARSED_ARGUMENTS} -I ${CMAKE_CURRENT_SOURCE_DIR}
     ${tblgen_includes}
     ${LLVM_TABLEGEN_FLAGS}
     ${LLVM_TARGET_DEFINITIONS_ABSOLUTE}
     ${tblgen_change_flag}
     ${additional_cmdline}
     # The file in LLVM_TARGET_DEFINITIONS may be not in the current
     # directory and local_tds may not contain it, so we must
     # explicitly list it here:
-    DEPENDS ${tablegen_depends}
+    DEPENDS ${ARG_DEPENDS} ${tablegen_depends}
       ${local_tds} ${global_tds}
     ${LLVM_TARGET_DEFINITIONS_ABSOLUTE}
     ${LLVM_TARGET_DEPENDS}
     COMMENT "Building ${ofn}..."
     )
 
   # `make clean' must remove all those generated files:
   set_property(DIRECTORY APPEND PROPERTY ADDITIONAL_MAKE_CLEAN_FILES ${ofn})